1. Field of the Invention
The present invention generally relates to magnetic storage devices. More particularly, some embodiments relate to creating discrete media tracks in magnetic storage devices via permanent magnetic stress erasure.
2. Related Technology
During recent years, there has been a steady improvement in the volume of data that can be stored on magnetic storage media, such as hard disk drives used in computers. Today, a single 3.5 inch magnetic storage disk can store 250 gigabytes or more of data. At the same time, storage capacity per unit cost has fallen dramatically, which has enabled individual users and enterprises to radically change the way in which data is recorded and stored. Indeed, the ability to store large volumes of data inexpensively has been a driving factor in the information technology revolution during recent decades.
Conventional storage media include solid-state devices, drive arrays (RAID), single rotating magnetic disk drives, and removable optical media. FIG. 1 is a graph that illustrates tradeoffs between performance and cost associated with typical storage media used in combination with computers. As shown, removable optical storage devices, such as optical read-only or read-write disks, generally provide the least expensive alternative for storing large amounts of data. However, single rotating magnetic devices, such as hard disk drives used in large numbers of personal computers, provide mass storage that is almost as cost effective as removable optical devices, but with better performance. In this context, the term “performance” relates primarily to the reliability and access times associated with the various storage media. As shown in FIG. 1, however, the performance of single rotating magnetic storage devices is increasing less rapidly than the performance of RAID and solid-state devices.
The issue of magnetic isolation of bits on the recording surface of hard disk drives limits the growth in bit and track density. Thermal stability limits the grain size of the media, which in turn limits the bit cell dimensions due to edge geometry and inter-granular coupling. Control of head geometries and stray leakage flux at the track edges further complicates the issues, and limits the signal to noise ratio gains with improved write flux due to side writing. Conventional methods of isolating grains during media deposition and improving thermal stability are reaching physical limits and the need to further isolate tracks and bits is required for further density gains.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.